Gas turbine engines may be employed to power various devices. For example, a gas turbine engine may be employed to power a mobile platform, such as an aircraft. In certain examples, gas turbine engines include a radial turbine positioned immediately downstream of a combustion section of the gas turbine engine. Generally, higher radial turbine inlet temperature and higher radial turbine engine speed are required to improve gas turbine engine efficiency. Increased speeds and higher temperatures, however, may increase a risk of oxidation of a blade of the radial turbine and may increase mechanical stress resulting from centrifugal forces acting on the radial turbine blade.
Accordingly, it is desirable to provide improved cooling for a radial turbine blade using a diverging-converging cooling passage, which cools the radial turbine blade while withstanding the centrifugal forces acting on the radial turbine blade. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.